Device for collecting washing fluid from a jet power plant wash

ABSTRACT

The subject of the invention is a device for collecting washing fluid from a jet power plant wash, with a collecting receptacle for washing fluid for arranging beneath the jet power plant ( 10 ) and/or behind the exhaust end of the jet power plant. According to the invention, the following features are provided
         a) the collecting receptacle has at least two interconnectable collecting receptacle modules ( 1 );   b) the collecting receptacle modules ( 1 ) in the in-use state are detachably interconnected to form a collecting receptacle;   c) the device has a fixture ( 12, 13 ) for positioning the collecting receptacle beneath the jet power plant and/or behind the exhaust end of the jet power plant.

The invention refers to a device for collecting washing fluid from a jetpower plant wash, with a collecting receptacle for washing fluid forarranging beneath the jet power plant and/or behind the exhaust end ofthe jet power plant.

Jet power plants of commercial subsonic transport aircraft are todaywidely predominantly so-called turbofan jet power plants. Such aturbofan power plant has a so-called core engine in which the actualcombustion process of the kerosene is carried out. The core engine in aknown manner has one or more compressor stages, a combustion chamber,and also one or more turbine stages in which the hot combustion gasesyield some of their mechanical energy. This mechanical energy for onething is required for driving the compressor stages, and for anotherthing a so-called turbofan, which is arranged upstream, is driven by thecore engine and as a rule has a significantly larger diameter than thecore engine, and allows a considerable part of the air which flowsthrough the power plant as a whole to bypass the core engine asso-called bypass airflow or secondary airflow. The turbofan makes up asignificant part of the thrust power of the power plant via this bypassairflow, and in addition the high bypass airflow portion provides for abetter environmental compatibility of the power plant, especially abetter efficiency at subsonic speeds, and also an improved noisesuppression of the hot exhaust gas flow of the core engine.

Jet power plants, during operation, are contaminated as a result ofcombustion residues of the core engine, and also as a result of aircontaminants which are drawn in with the combustion or bypass air, suchas dust, insects, saline fog, or other environmental contaminants. Thesecontaminants especially also form a coating on the rotor blades and/orstator blades of the compressor of the core engine, which impairs thesurface quality and, as a result, ultimately the thermodynamicefficiency of the power plant.

For removing the contaminants, jet power plants are cleaned. It is knownfrom WO 2005/077554 A1 to arrange a multiplicity of cleaning nozzlesupstream of the fan of a turbofan power plant for this purpose in orderto thus clean the fan and the core engine.

The contaminated cleaning fluid as a rule is collected. For thispurpose, it is known for example from U.S. Pat. No. 7,297,260 B2 toarrange behind the propulsive nozzle of a jet power plant a fluidseparator which separates out the fluid portion of the aerosol whichissues from the propulsive nozzle. In addition, a drip tray is arrangedover a wide area beneath the jet power plant in order to collectcleaning fluid which drains out of the cowling.

The invention is based on the object of creating a device for collectingwashing fluid of the type referred to in the introduction, which isinexpensive and simple and convenient to handle.

According to the invention, the following features are provided:

-   -   a) the collecting receptacle has at least two interconnectable        collecting receptacle modules;    -   b) the collecting receptacle modules are detachably        interconnected to form a collecting receptacle in the in-use        state;    -   c) the device has a fixture for positioning the collecting        receptacle beneath the jet power plant and/or behind the exhaust        end of the jet power plant.

First of all, some terms which are used within the scope of theinvention are to be explained.

With a device according to the invention, washing fluid from a jet powerplant wash is to be collected. During such a jet power plant wash, as arule finely distributed fluid (preferably water, which is mixed withcleaning agents if necessary) is sprayed under increased pressurethrough the front air intake into the jet power plant, especially intothe so-called core engine. A suitable device is described for example inEP 7 005 446.5. A part of this cleaning fluid discharges again asaerosol from the rear propulsive nozzle of the core engine of the jetpower plant. Another part (as a rule the larger part of typically about70%) of the cleaning fluid is first of all separated out inside the jetpower plant, runs downwards, and drains out again for example throughopenings in the cowling of the jet power plant, out of the rear openingof the cowling, out of the secondary airflow exit, or out of thepropulsive nozzle of the core engine. Since this fluid may becontaminated with impurities, it should be collected.

The term “jet power plants”, in the context of the invention, refers toany airplane power plants which include a gas turbine. They may alsopossibly be turboprop power plants.

The collecting receptacle according to the invention for washing fluidis designed for collecting draining-out washing fluid, and also forreceiving an aerosol, which falls on account of gravity force, behindthe propulsive nozzle of the power plant. The collecting receptacle istherefore essentially open on its side which points upwards in thein-use state, or has suitable collecting surfaces.

The collecting receptacle is provided for arranging beneath the jetpower plant and/or behind the exhaust end of the jet power plant. Theterm “arranging beneath the jet power plant” is to be functionallyunderstood and relates to an arrangement of the collecting receptaclewhich during a cleaning of the respective jet power plant completelycollects, or largely collects, washing fluid which drains out.

An arrangement behind the exhaust end of the jet power plant, especiallybehind the exhaust end of the propulsive nozzle, allows collecting ofthe falling fluid aerosol which issues from the propulsive nozzle.

According to the invention, provision is made for the collectingreceptacle to have at least two interconnectable collecting receptaclemodules. In the in-use state of the device, these collecting receptaclemodules are detachably interconnected to form a collecting receptacle.The modular construction of the collecting receptacle enables simple andspace-saving transporting and storing of the collecting receptacle. Inthe in-use state, two or more (preferably 3 to 5, especially preferably4) modules can be detachably interconnected to form a collectingreceptacle which is arranged beneath and behind the jet power plantwhich is to be cleaned.

A jet power plant may have an axial length of about for example 5 m fromthe air intake to the exhaust of the propulsive nozzle. Washing fluidwhich drains out should preferably be collected over the entire lengthof the jet power plant during the cleaning process. In addition, thecollecting receptacle should reach by about 2 to 4 m behind the exhaustend of the jet power plant in order to collect at least a large part ofthe aerosol which issues from the gas nozzle. The overall length of acollecting receptacle according to the invention can therefore be forexample 7 to 10 m, and preferably 8 or 9 m. Another rule of thumb forthe dimensioning of the overall length is the axial length of the jetpower plant which is to be cleaned, plus a length of 2 to 6 m, morepreferably 2 to 5 or 2 to 4 m.

The term “fixture for positioning the collecting receptacle beneath thejet power plant and/or behind the exhaust end of the jet power plant”refers to any device which is suitable for setting and maintaining adefined position of the collecting receptacle relative to the jet powerplant which is to be cleaned. The collecting receptacle can bepositioned without physical connection to the jet power plant which isto be cleaned, for example by maneuvering a suitable trolley beneath thepower plant which is to be cleaned, wherein the trolley carries thecollecting receptacle. Within the scope of the invention, however, it ispreferred that the collecting receptacle is physically attached to partsof the power plant which is to be cleaned and is supported by this, aswill be explained in more detail below.

The invention is based on the surprising knowledge that for largelycomplete collecting of the washing fluid when cleaning a jet powerplant, the complex and costly separating device, which is assumednecessary in the prior art (U.S. Pat. No. 7,297,260 B2), for separatingout the fluid portion from the aerosol which issues from the propulsivenozzle, is not necessary. The invention has realized that during acleaning process the fluid portion of the aerosol has already fallen dueto gravity force a few meters behind the exhaust of the propulsivenozzle to such an extent that it is collected by the collectingreceptacle according to the invention. As already described above, forthis purpose the collecting receptacle extends preferably by the saiddistance in the axial direction behind the exhaust end of the jet powerplant.

A further aspect of the invention is the modular construction of thecollecting receptacle. Since a typical overall length of a collectingreceptacle according to the invention is about 8 to 9 m in the in-usestate, such a receptacle as a whole is costly in handling duringtransportation and storage. The modular construction according to theinvention enables a simpler and space-saving handling duringtransportation and storage.

The collecting receptacle is preferably formed in a longitudinallyextended manner in the direction of view from above. This means that inthe in-use state its longitudinal extent, as seen horizontally fromabove, with which it is arranged in the longitudinal axis of the jetpower plant beneath this power plant, is considerably greater than itswidth perpendicularly to this longitudinal axis. The said factor ispreferably 3 to 20, more preferably 5 to 15, and more preferably 6 to12. Preferred lengths of the collecting receptacle have already beenreferred to above, preferred ranges for the width being 0.5 to 3 m, morepreferably 0.6 to 2 m, more preferably 0.7 to 1.5 m, and more preferably0.8 to 1.2 m.

The invention has realized that such a comparatively narrow collectingreceptacle is adequate on the one hand to collect the largest part ofthe washing fluid which drains out of the jet power plant since thisdischarges essentially at the lowest points of the power plant. On theother hand, however, the largest part of the aerosol which issues fromthe propulsive nozzle is also collected since this aerosol is not widelydistributed and therefore is deposited only to an insignificant degreenear to the collecting receptacle. According to the invention, about 90%of the washing fluid which is introduced can be collected. It isunderstood that this portion depends significantly upon theenvironmental conditions which prevail during the washing process. Athigh outside temperatures, and when using a water-based washing fluid, aconsiderably larger part of the finely distributed water droplets isperhaps evaporated and cannot be collected.

Within the scope of the invention, it is preferred if the collectingreceptacle has a weight which is as low as possible. For a weight-savingconstruction, it can be advantageous that each collecting receptaclemodule has a frame which imparts structural strength to it. Such a framecan be built from plastic or metal profiles. Fiber-reinforced plasticsor light metals such as aluminum or aluminum alloys, are preferred forthe material of the frame. The frame sections can be interconnected in afixed manner, for example welded, but they can also be detachablyinterconnected so that the frame is collapsible.

The frame preferably supports a flexible receptacle sheeting which isdesigned for collecting the washing fluid. The actual receptacle istherefore formed by means of this flexible receptacle sheeting. Thisembodiment of the invention enables a particularly lightweight type ofconstruction since the receptacle sheeting has a low weight per unitarea and the overall structural strength of the collecting receptacle isensured by means of the similarly lightweight frame. As receptaclesheeting, a plastic sheeting which is known in the prior art ispreferably used, which is sufficiently stable and tear-resistant for theintended application and has an adequate resistance to constituents ofthe washing fluid. Depending upon the intended application, adequateUV-stability can also be of importance if power plant washes areconducted in the open.

The type of construction according to the invention enables a verylightweight construction of a collecting receptacle. A collectingreceptacle, which is described in more detail in the exemplaryembodiments below and consists of four modules which have an aluminumframe in each case, with a length in total of 8.40 m and a width ofabout 1 m, has an overall weight of only 23 kg. If a carbon fiber frameis used, this weight can be reduced to about 16 kg. Therefore, a weightof the collecting receptacle of under 50 kg, more preferably under 40 orunder 30 kg, is preferred. Such light collecting receptacles can readilybe fastened in the in-use state on the jet power plant and supported bythis.

Within the scope of the invention, the receptacle sheeting can bedetachably connected to the frame. In the case of a collapsible frame,for example frame profile sections can be pushed through supportingsections or supporting loops of the receptacle sheeting. In the case ofa fixed frame, which is not collapsible within the limits of normal useof the device according to the invention, the receptacle sheeting can belooped for example over frame sections and welded to another sheetingsection, or alternatively releasable connections such as hook-and-loopstrips or the like can be provided.

Within the scope of the invention, it is preferred that each collectingreceptacle module has at least one and preferably at least two or threefluid drains. In this way, it is to be ensured that during the washingprocess the largest part of the collected washing fluid can immediatelybe carried away by means of the drains and the weight of the collectingreceptacle is only insignificantly increased as a result of thecollected water. The said arrangement of a larger number of fluid drainsachieves the effect of the largest part of the washing fluid being ableto immediately drain away regardless of the accurate arrangement andalignment of each collecting receptacle module and not being able toaccumulate at one point of a collecting receptacle module at which thereis no drain.

Each collecting receptacle module can preferably form a top-open driptray. In the assembled in-use state of the collecting receptacle, theedges of the trays adjoin each other, or abut against each other, andform an essentially large-area collecting receptacle.

According to an especially preferred variant of the invention, thecollecting receptacle modules in a collapsed stowing state can bestacked one inside the other. For this purpose, provision can be madefor each collecting receptacle module to have slightly differentexternal dimensions in such a way that stacking one inside the other ispossible. For example, in the case of a collecting receptacle consistingof four modules each module can be slightly shorter in the axialdirection and slightly narrower transversely to this axial directioncompared with the module adjoining on one side, so that this module canbe inserted into the respective larger module and therefore stacked. Inthe assembled in-use state, the modules can be interconnected in asuitable way, for example the frames can be screwed to each other bymeans of simply manageable quick-release fasteners or wing nuts or thelike, or can be connected in another way.

If the modules can be stacked one inside the other, as described above,the collecting receptacle can taper as a whole on account of thereducing width of each module in comparison to the preceding module. Itis preferred, therefore, that the wider side of the collectingreceptacle points rearwards in the in-use state in the gas flowdirection of the jet power plant which is to be cleaned in order to forma collecting receptacle which is as wide as possible behind the jet exitof the power plant.

It is preferred that the collecting receptacle modules in the assembledin-use state are not in fluid communication with each other. This meansthat the fluid cannot flow from a collecting receptacle module directlyinto the adjoining module. This is possible for example by means of thedescribed design of each collecting receptacle module as a separate driptray. In this way, a one-sided weight loading of the collectingreceptacle as a result of washing fluid accumulating in a corner or onone side is largely avoided. Alternatively, it is possible that thecollecting receptacle modules in the in-use state form a large commonfluid receptacle in which no fluid separation between the modules takesplace.

If two collecting receptacle modules in the in-use state abut againsteach other, without there being a fluid connection between them, adiverting device can be provided, which diverts the washing fluid whichimpinges upon the region between two adjoining modules into at least oneof these collecting receptacle modules. For example, it can be asheeting section which is folded over the delimiting region of theadjoining modules and ensures that impinging fluid flows into one of thetwo collecting receptacle modules.

It is preferred that the device according to the invention is positionedin a desired manner beneath and/or behind the exhaust end of the jetpower plant by means of fixtures for detachable mounting of the deviceon a jet power plant. These fixtures for detachable mounting for examplecan engage on the cowling, on the air intake of the turbofan and/or onthe air exhaust of the propulsive nozzle of the jet power plant. Formounting on the cowling, for example vacuum suckers or suction cups canbe provided. These can reliably support a collecting receptacleaccording to the invention on account of the low weight.

For mounting on the air intake of the turbofan and/or on the gas or airexhaust of the propulsive nozzle of the jet power plant, suitablehooking devices or clamping claws can be provided, which can preferablybe covered with a soft material, such as plastic, so as not to damagethe corresponding power plant parts.

The said positioning fixtures can preferably have devices for settingthe inclination of the collecting receptacle relative to the horizontal,and also for the spacing of the collecting receptacle in the verticalrelative to the jet power plant. A positioning which is as close aspossible beneath the jet power plant has the advantage that during thewashing process aerosol which issues from the propulsive nozzle iscollected before it is widely distributed, for example on account ofwind or the like, when falling to the ground.

An exemplary embodiment of the invention is described in the followingtext with reference to the drawings.

In the drawings:

FIG. 1 schematically shows a device according to the invention inlongitudinal section, mounted on a power plant;

FIG. 2 schematically shows a view of the device from underneath;

FIG. 3 shows a cross section of the device, mounted on the power plant;

FIG. 4 shows in a detailed view from FIG. 3 the mounting of the deviceon the jet power plant;

FIG. 5 shows a view of the frame of two collecting receptacle modulesaccording to the invention;

FIG. 6 shows in a view from above the frame of four collectingreceptacle modules which are mounted to form a collecting receptacle;

FIG. 7 shows two receptacle sheeting inserts for collecting receptaclemodules.

FIG. 5 shows the frames of two collecting receptacle modules 1. Eachframe has corner profiles 2 which are connected to longitudinallyextended profiles 3 to form an altogether cubic rigid frame. The cornerprofiles 2 and the associated longitudinally extended profiles 3 arepreferably detachably interconnected, for example screwed together, butare preferably not disassembled during the customary use, and duringtransportation and storage of the device according to the invention.

FIG. 7 shows two receptacle sheeting inserts, which as a whole areidentified by 4, for the frame of a collecting receptacle. Such areceptacle sheeting insert 4 forms a tray, and a multiplicity ofsealable drains 5 are provided at the bottom of this tray. On the fourupper edges of each receptacle sheeting tray, preferablyhollow-cylindrical holders, or holding loops 6, are arranged, into whichthe associated longitudinal profiles 3 of the frame can be inserted.

The holders 6 of the receptacle sheeting trays 4 can be formed by therespective sheeting edge being turned over and being permanentlyconnected to the inner side of the corresponding mating sheeting forexample by welding, by adhesive fastening, or in another way. In thiscase, for mounting a collecting receptacle module the associated framehas to be collapsed and the longitudinal profiles 3 inserted into theassociated holders 6 of the receptacle sheeting tray 4. The frame isthen assembled, during which the longitudinal profiles 3 are connectedto the corner profiles 2. In this form, the collecting receptaclemodules can be mounted.

Alternatively, it is possible to releasably design the frame loops 6 ofa receptacle sheeting tray, for example by means of hook-and-loopfasteners, slide fasteners, or the like.

Each receptacle sheeting tray, on one short edge, has a sheeting strip 7which for example can be provided with a hook-and-loop strip at 8. Thissheeting edge 7 bridges the region between two adjoining collectingreceptacle modules in the mounted state of the collecting receptacle,and ensures that fluid which impinges there is diverted into one of thetwo collecting receptacle modules.

The corner profiles 2 of each frame have screwed connections, indicatedby 9, by which two collecting receptacle modules can be screwed to eachother on their short sides. Wing nuts or the like, which enable a simpleassembly and disassembly without tools, are preferably used for thescrew fastening. It is understood that other suitable connections can beused apart from screwed connections.

As is to be seen in FIG. 6, four collecting receptacle modules which aremounted one upon the other form a longitudinally extended collectingreceptacle. The collecting receptacle modules in this case aresuccessively shorter and narrower (L1>L2>L3>L4, and B1>B2>B3>B4). Thissize difference is such that the collecting receptacle modules in thedisassembled state can be stacked one inside the other. Therefore, fortransportation and storage all four collecting receptacle modules can becommonly supported on a base area which corresponds to the base area ofthe largest collecting receptacle module with the length L1 and thewidth B1.

FIGS. 1 to 3 schematically show a device according to the invention witha collecting receptacle which is assembled from four collectingreceptacle modules and is mounted beneath a jet power plant 10. At leastone drain 5 of each collecting receptacle module is connected to a fluiddrain hose 11 which carries away the collected fluid. The fluid can becollected for example in a tank for reprocessing or disposal.

As is especially to be seen in FIG. 1, the device according to theinvention is attached beneath the jet power plant and supported by this.On account of the low weight of less than 30 kg, even under 20 kg whenforming the frames of the collecting receptacle modules fromfiber-reinforced plastic, the attachment on the power plant 10 can becarried out by hanging a suspension device, which is located at 12, inthe gas or air exhaust of the propulsive nozzle of the power plant 10,and also on the cowling of the power plant by means of suction cups 13.The attachment by means of suction cups 13 on the cowling of the powerplant is apparent in more detail from FIGS. 3 and 4. At a suitable pointof a collecting receptacle module 1, a cross beam 14 is attached on theupper side of the frame. This cross beam 14 can preferably be attachedat different points of the frame of the collecting receptacle modules inthe axial direction in order to enable an adaptation to different powerplants. The two sides of the cross beam 14 are connected via aheight-adjustment device 15 to the foot 16 of the suction cup 13. Thisfoot 16 is rotatable around the axis, which is indicated by 17, inrelation to the height-adjustment device 15 so that the angular positionof the suction cup 13 can be suitably set. The height-adjustment device15 can preferably be released by means of a quick-release fastener 18and be altered in its length so that the position and inclination of thecollecting receptacle beneath the power plant 10 can be set andadjusted.

For carrying out a power plant wash, the device according to theinvention is mounted and brought into the position which is shown inFIG. 1 beneath a power plant which is to be cleaned. Washing fluid isthen sprayed into the air intake of the power plant, preferablyespecially into the core engine. Washing fluid which drains down iscollected by means of the collecting receptacle and carried away bymeans of the hoses 11. Aerosol which issues from the gas exhaust of thepropulsive nozzle is deposited to a significant degree in the section ofthe collecting receptacle which projects beyond the exhaust end of thepower plant and is also carried away for disposal or reuse.

After carrying out the cleaning, the device according to the inventionis removed from the power plant. The four collecting receptacle moduleswhich are screwed together can be collapsed, stacked one inside theother and so transported away and stored in a simple manner.

1. A device for collecting washing fluid from a jet power plant wash,with a collecting receptacle for washing fluid for arranging beneath thejet power plant and/or behind the exhaust end of the jet power plant,characterized by the following features: a) the collecting receptaclehas at least two interconnectable collecting receptacle modules; b) thecollecting receptacle modules are detachably interconnected to form acollecting receptacle in the in-use state; c) the device has a fixturefor positioning the collecting receptacle beneath the jet power plantand/or behind the exhaust end of the jet power plant.
 2. The device asclaimed in claim 1, wherein the collecting receptacle is formed in alongitudinally extended manner in the direction of view from above. 3.The device as claimed in claim 2, wherein the longitudinal extent of thecollecting receptacle is greater than its width by the factor of 3 to20, preferably 5 to 15, and more preferably 6 to
 12. 4. The device asclaimed in one of claims 1 to 3, wherein each collecting receptaclemodule has a frame which imparts structural strength to it.
 5. Thedevice as claimed in claim 4, wherein the frame is collapsible.
 6. Thedevice as claimed in claim 4, wherein the frame supports a flexiblereceptacle sheeting which is designed for collecting the washing fluid.7. The device as claimed in claim 6, wherein the receptacle sheeting isdetachably connected to the frame.
 8. The device as claimed in one ofclaims 1 to 3, wherein each collecting receptacle module has at leastone and preferably at least two or three fluid drains.
 9. The device asclaimed in one of claims 1 to 3, wherein each collecting receptaclemodule in the assembled in-use state of the collecting receptacle is notin fluid communication with the further collecting receptacle modules.10. The device as claimed in one of claims 1 to 3, wherein eachcollecting receptacle module in the assembled in-use state of thecollecting receptacle forms a drip tray which abuts against the driptrays of the respectively adjoining collecting receptacle modules. 11.The device as claimed in one of claims 1 to 3, wherein the collectingreceptacle modules in a collapsed stowing state can be stacked oneinside the other.
 12. The device as claimed in claim 10, wherein adiverting device is provided for diverting the washing fluid whichimpinges upon the region between two adjoining collecting receptaclemodules into at least one of these collecting receptacle modules. 13.The device as claimed in one of claims 1 to 3, wherein the device forpositioning the collecting receptacle beneath the jet power plant and/orbehind the exhaust end of the jet power plant comprises fixtures fordetachable mounting of the device on a jet power plant.
 14. The deviceas claimed in claim 13, wherein the fixtures for the detachable mountingof the device on a jet power plant are designed for mounting on thecowling, on the air intake of the turbofan and/or on the air exhaust ofthe propulsive nozzle of the jet power plant.
 15. The device as claimedin claim 14, wherein the fixtures for the mounting on the cowlingcomprise vacuum suckers.
 16. The device as claimed in claim 14, whereinthe fixtures for the mounting on the air intake of the turbofan and/oron the air exhaust of the propulsive nozzle of the jet power plantcomprise hooking devices.
 17. The device as claimed in one of claims 1to 3, wherein the device for positioning the collecting receptaclebeneath the jet power plant and/or behind the exhaust end of the jetpower plant comprises devices for setting the inclination of thecollecting receptacle to the horizontal.